FREDERICK, Md. (WJZ) –– A 19-year-old Thurmont man is charged in the first-degree murder of Curtis Mason Smith.

Charging documents said evidence found in his home was consistent with a possible larger plot: the intent of committing a mass shooting and/or mass casualty event.

READ MORE: Missing 19-Year-Old Curtis 'Mason' Smith Found Dead In Frederick County

The Frederick County Sheriff’s County arrested Joshua David Eckenrode after a two-day investigation and multiple witness interviews and warrants.

Eckenrode was also charged with firearm use in a violent crime.

Smith, 19, of Frederick, was reported missing over the weekend.

“Our detectives and deputies, along with officers from the Frederick Police Department, have been working around the clock to solve this murder,” said Lt. Andy Crone, FCSO Criminal Investigations commander. “These professionals worked every lead, tip, and call they received and through their investigative efforts this person was quickly identified and detained.”

Detectives gathered enough evidence to executive search and seizure late Monday on two separate residences associated with Eckenrode. There, they found multiple weapons and explosive materials.

“They found 40 plus weapons,” Todd Wivell, of the Frederick County Sheriff’s Office, said. “There were notes left, and those notes point to the fact that he was staging stuff, he was thinking about how he was going to do this.”

The Sheriff’s Office worked with the Office of the State Fire Marshal to render the devices safe. There is no threat to the community.

READ MORE: Notes Found Among Frederick Murder Suspect Joshua David Eckenrode's Things Suggested He Was Planning Mass Casualty Event, Sheriff Says

Police also found blood-soaked towels and stained clothes at the home.

FCSO detectives initially held Eckenrode on the charges of possession of destructive devices, possession of a firearm, and possession of explosives without a license. As the investigation continued throughout the two days, FCSO detectives obtained enough evidence for the 1st-degree murder and firearm charges. Deputies transported Eckenrode to the Frederick County Adult Detention Center for holding.

Charging documents said this evidence was consistent with Eckenrode possibly intending on committing a mass shooting and/or mass casualty event.

Neighbors were in disbelief that this all happened across the street.

“It is very disheartening and very concerning that the individual lives that close to a neighborhood like this,” said Randy Turner, a neighbor.

“I went to the movies,  I saw the boy hosing the driveway down,” another neighbor said.

As this investigation is still ongoing, we ask that anyone having information related to this case contact the FCSO tip line at 301-600-4131 and reference case # 21-025637.

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Kelsey Kushner